I open-sourced DomA: an AI automation agent for the browser

yin shen — Wed, 14 Oct 2026 16:14:12 +0000

Most “AI browser” products ask you to abandon the browser you already live in.

New Chromium fork. New profile. Friction with passwords, extensions, and muscle memory. Your logged-in sessions don’t come along for the ride.
DomA takes the opposite bet: stay in Chrome (or Edge), keep the tab you’re already on, and run an agent from a side panel.

That’s why we open-sourced it.

GitHub: https://github.com/dom-actions/doma
Idea we mean literally: conversation is action

The real pain isn’t “can it click?” — it’s accuracy

Browser agents often look impressive in demos and fall apart on real sites:

Every micro-step round-trips to the main LLM (slow + context drift)
Overlays, suggest boxes, shadow DOM, and CSP break brittle selectors
Successful workflows don’t compound — you re-solve the same site next week

DomA’s open core is built around two answers to that pain: Jev inner loops and solidified Skills.

Meet you where you are (extension, not a fork)

DomA is a Chrome/Edge extension, not a standalone AI browser and not a hosted “cloud browser.”
You keep:

bookmarks and extensions
existing logins / cookies
the browser you already trust day-to-day You chat in the side panel. The agent grounds on the page, then acts: click, type, navigate, collect, multi-step flows.

BYOK (secondary, but intentional)

The open edition is Bring Your Own Key: OpenAI-compatible providers (and similar endpoints).

You’re not locked into our model marketplace. Keys stay in your setup; model calls go to your chosen provider.
(That’s important for developers — but the product thesis is still “agent in your browser,” not “BYOK for its own sake.”)

How DomA perceives and acts

Set-of-Mark (SoM) grounding

Interactive elements get numbered overlays. The model sees a screenshot with markers and chooses index-based actions instead of guessing fragile CSS selectors.

Multi-strategy execution

Synthetic events for speed, CDP fallbacks for stubborn widgets, and coordinate-level interaction when needed.

Context hygiene

Large tool payloads can be spilled out of the chat transcript and re-read via refs — so long tasks don’t drown the model in noise.

Accuracy lever #1 — Jev inner loops

Classic agent loops look like:

screenshot → main LLM → click → screenshot → main LLM → type → …
That burns latency and invites inconsistency between steps.

Jev is DomA’s optional inner loop on browser_screenshot (act/verify):

Given a goal, it can decide and execute multiple grounded steps inside the tool
Refresh SoM → choose click/type → act → continue until the goal progresses or it must hand back
Verify passes can check whether the page actually moved toward the goal Net effect: fewer main-LLM round trips for the boring middle of a form/flow, and tighter coupling between perception and action — which is where a lot of “almost right” failures come from. Jev doesn’t magically solve every site. It attacks the failure mode of over-delegating every micro-action to a chatty outer loop.

Accuracy lever #2 — solidified Skills

Even with good grounding, accuracy compounds only if successful procedures become reusable.
DomA supports Agent Skills:

Capture a workflow that worked on a real site (instructions, constraints, host rules)
Load it later with browser_invoke_agent_skill instead of re-deriving the plan from scratch
Treat skills as living playbooks — site-specific heuristics, not one-off chat luck This is how you move from “the model might figure it out” to “this site has a known reliable path.” If browser automation feels unreliable, it’s often because the system has perception + actions, but no durable procedural memory. Skills are that layer.

What’s in the open-source edition

Side-panel chat → tool-calling browser agent
SoM screenshot loop + click/type/navigate tools
Jev-style inner act/verify looping (when enabled)
Skills for reusable site/task procedures
Build from source or load a prebuilt package from Releases

There is also a commercial store build with extras (video download, userscripts, ad blocking, …). This post is about the open core.

DEV Community: yin shen